Twenty years after Princess Diana's iconic visit to a minefield in Angola, the world faces a new land-mine crisis in Syria and Iraq on a scale not seen for decades, campaigners said on Sunday.

The Mines Advisory Group said it had cleared and destroyed more than 9,000 newly laid land mines in both countries in the past six months in areas formerly occupied by the Islamic State militant group.

Jane Cocking, the group's chief executive, said at least $100 million of additional funding will be needed per year to tackle both newly laid land mines and those still in the soil from previous conflicts in more than 60 countries.